Prince Henry, Duke of Gloucester (Henry William Frederick Albert; 31 March 190010 June 1974) was a soldier and third son of King George V and Queen Mary.

He was appointed potential regent for his niece, Princess Elizabeth (later Queen Elizabeth II), when his brother, King George VI, came to the throne in 1936. He was required to stay in the United Kingdom until Elizabeth came of age in case her father died and she ascended the throne as a minor.

The Duke served as a soldier for most of his life. He was also the 11thGovernor-General of Australia, from 1945 to 1947. At his death in 1974, he was the last surviving knight of the Order of St. Patrick, as well as the last surviving child of King George V and Queen Mary.